ARCTIC PLANTS IN OLD LAKE DEPOSITS OF SCOTLAND 49 



circular bodies, supposed to be statoblasts of a freshwater 

 Polyzoon, also much of the chitine of Daphnia, like mica 

 scales, and many black shining bodies, like black diamond 

 dust, said to be water-mites. 



5. A series of coarse sands, gravels, and silts, 8 or 

 10 feet in thickness, in which hazel nuts, acorns, alder seed- 

 cones, and stones of fruits abounded, with much drift-wood 

 in the shape of twigs, pieces of bark of trees, and in two or 

 three cases tree trunks 8 or 10 inches in diameter. 



6. Five or six feet of ochrey sand with only holes formed 

 by rootlets in it, but containing no actual organic remains. 



7. Vegetable soil, 2 feet or so in thickness. 



Such is a rough account of the section at Hailes, which 

 shows deposits made in a lake extending from the times of 

 the boulder drift up to recent times. 



Ere I pass from it I may note that in a fine silt or mud 

 near the bottom several species of freshwater mollusca, one 

 or two land shells, and several species of Ostracoda were 

 found in 1886, as recorded in the " Ancient Lakes of Edin- 

 burgh" (Proc. Roy. P/ij/s. Soc., vol. x. pp. 135-145). It is 

 there also stated that two large boulders, 4 or 5 feet in 

 diameter, occurred in the lake deposits in such a way as 

 proved that they must have been deposited in it after the 

 lake had been for some time in existence. Lately some of 

 the vegetable drift which is stated to have been found in the 

 cleft between the two boulders has been re-examined, and 

 Apus remains have proved to be abundant in it, as well as 

 fragments of the Arctic leaves. This further confirms the 

 view as to the period of their deposition. 



The extent of the lake at Hailes cannot be given with 

 any precision, as we cannot say how far it extended over the 

 rock which has been quarried away. But it cannot have 

 been extensive, and must have been a tarn, or lochan, as Mr. 

 Reid has described it. 



The course of events in Hailes is simple and easily read. 

 First existed a small pool or tarn in which water-plants 

 grew, and into which Arctic land-plants were drifted, and in 

 which some few freshwater shells lived and the Apus crawled 

 in great numbers. Into this a current of water flowed, 

 bringing the drift-wood, the hazel nuts and fruit-stones, 

 9 E 



